Research integrity

Image presentation for scholarly communications and grant applications

These guidelines are mostly taken from the EMBO Molecular Medicine Guidelines for Authors and are intended to complement or integrate specific indications from funding agencies and scholarly journals. The ultimate goal is to ensure data integrity and reliability and to protect OSR investigators from unfounded post-publication allegations of misconduct originating from non-malicious but poor image processing and handling.

Image-based data (gels, micrograph photographs, etc.) should be scanned or captured at the highest resolution possible and saved in lossless formats. This can be achieved by saving images as TIFF while ensuring that no compression option is selected in the application used for acquisition/export of the images. It should be noted that 300 dpi at print size is usually considered the lowest acceptable resolution for original images for most journals; therefore, the default settings on imagers, scanners, and cameras should always be checked. Screenshots should never be used to capture images. If image file size is a concern, it is best to use lossless image compression such as LZW and in any case, to avoid quality-degrading compression formats such as JPEG. This is important because failure to provide sufficiently high-quality images leads to delays in publication, also due to the impossibility to verify data integrity. Many issues related to image quality, resolution (e.g. compiled figure vs. image resolution), format and others are due to misunderstanding of these basic concepts. It is therefore suggested that authors familiarise themselves with them, and may wish to refer to detailed resources on the topic from EMBO Press and The Journal of Cell Biology.

In preparation for submission e.g. of a manuscript to a journal or a grant application to a funding agency, a certain degree of image processing is acceptable (and for some experiments, fields and techniques unavoidable), but should be minimal (for instance, to add arrows to a micrograph) and the final image must accurately reflect the original data and conform to community standards.

The corresponding author should retain unprocessed (source) data and metadata files and be prepared to promptly make them available, as editors or any authorised office/person may request them at any time. It should be noted that if source data are unavailable, further consideration of a submitted manuscript may be stalled until resolution of the issue or stopped altogether.

It is suggested that the authors list all image acquisition tools and image processing software packages used in the preparation of figures and store this information in the README file associated with the manuscript folder. Authors should also document, or be prepared to document upon request, key image-gathering settings and processing steps in the Methods or other section of the manuscript, depending on journal policy.

Images gathered at different times or from different locations should not be combined into a single image, unless it is stated that the resultant image is a product of time-averaged data or a time-lapse sequence. If juxtaposing images is nonetheless deemed essential, the borders should be clearly demarcated in the figure and described in the legend. Typical scenarios in this respect are the “splicing” in of western blot sections and combination of different image fields into a single image (see further below).

The use of touch-up tools, e.g. cloning and healing tools in Photoshop or any other tool that deliberately conceals manipulations, must be avoided.

Image processing (e.g. changing brightness and contrast) is to be used with restraint and should not cause data loss (see further below). Furthermore, it is appropriate only when applied equally across the entire image including controls. In fact, processing to emphasize one region in the image at the expense of others is inappropriate and can amount to data falsification.

The policies for image processing and handling in reputable journals are quite stringent and provide clear instructions on responsible conduct and disclosure when certain image manipulations are necessary. For instance, the display of cropped gels and blots in a manuscript is usually permitted when aimed at improving the clarity of the presentation. Nevertheless, even when journal policies may be more permissive, OSR investigators should respect the following general data integrity indications for image presentation.